Lisa Schnirring 
Staff Writer
Staff Writer
Dec 7, 2012 (CIDRAP News) – Influenza C generally isn't thought to
be a cause clinically significant disease, but a study in Italian
children who were seen in the emergency department for pneumonia found
the virus in five children, with a disease severity that resembled
influenza A.
The study evaluated data from four flu seasons from 2008-09 to
2011-12 at a pediatric clinic in Milan and appeared today in an early
online edition of Influenza and Other Respiratory Viruses.
Influenza C can infect humans and pigs, and infections are rare compared with influenza A and B.
The researchers included healthy children from ages 1 month to 14
years who were seen because of fever and lower respiratory tract
symptoms and whose chest radiographs suggested community-acquired
pneumonia. Respiratory swabs and sera were collected, and researchers
noted patients' clinical information and whether each child was
hospitalized.
Respiratory samples were tested for influenza A, B, and C, and the
samples that tested positive were tested for several other viral
coinfections. Researchers sequenced the positive influenza C samples to
determine the lineage.
Of 391 children included in the study, influenza C was identified
in 5 (1.3%). Influenza A was detected in 26 children, and influenza B
was found in 3. Influenza C was found only during two of the four
seasons: 2008-09 and 2009-10.
Four of the children with influenza C were younger than 3 years
old, and one was 14 years old. No viral coinfections were found in the
children who had influenza C.
All of the children with influenza C infections were hospitalized,
but their clinical symptoms improved a few days later. Researchers
observed that the severity of influenza C symptoms was similar to those
for influenza A, but worse than in kids with pneumonia related to
influenza B. All children with influenza C pneumonia recovered with no
disease recurrence, according to the study.
Phylogenetic analysis showed that the five influenza C viruses
clustered in two of the six lineages: Kanagawa/1/76 and Sao
Paulo/378/82.
The group wrote that the study is the first that they know of that
gauges the importance of influenza C in pediatric community-acquired
pneumonia. However, they noted that further study is needed to determine
what role influenza C plays during other parts of the year, given that
previous studies have shown that the virus doesn't have the same
seasonal pattern as the other two flu types.
Though the similar clinical pictures between influenza A and
influenza C have been found in other studies, the role of influenza C is
notable, especially since it can be an important cause of
community-acquired pneumonia in kids, the authors write.
The findings of the study have parallels to a 2006 study on
hospitalized Spanish infants conducted from September 1999 through July
2003, which found influenza C infections in six of 706 children.
Three of the six, however, had viral coinfections, and the earlier
study did not focus exclusively on community-acquired pneumonia. As
with the Italian study, though, the influenza C infections in the
Spanish study were clinically similar to influenza A infections.
Principi N, Scala A, Daleno C, et al. Influenza C virus-associated community-acquired pneumonia in children. Influenza Other Respi Viruses 2012 Dec 7 [Abstract]
See also:
October 2006 Emerg Infect Dis letter
No comments:
Post a Comment